ATMS Precipitable Water
Frequently Asked Questions about the ATMS Precipitable Water Product
1) What is this product?
This product outputs instantaneous total precipitable water amounts from the S-NPP and JPSS satellites in mm. It is useful when trying to identify how much moisture is contained vertically in a column of atmosphere. Very moist air masses can provide moisture to fuel deep convection. It is also helpful when identifying atmospheric rivers, monsoon flow, and moisture boundaries. This can inform decisions on flash flooding as well as severe weather.
2) How often do I receive this data?
The S-NPP satellite is part of the Afternoon Train (A-Train) of satellites. It crosses your area at ~1:30am and ~1:30pm local time every day.
3) How do I display this product in AWIPS-II?
To display this product, go to the "Satellite" menu in CAVE. Next, select "S-NPP," and from there select "Total Precipitable Water".
4) How do I interpret the color maps associated with this product?
Product-specific color maps have not yet been created for this product.
5) What should I use in conjunction with this product to produce a better forecast?
Geostationary satellite TPW estimates, other polar-orbiting satellite TPW estimates (if they sample the same area in a reasonable timeframe), model-derived TPW fields, and blended TPW fields (to better understand its individual components).
6) How is this product created?
The Advanced Technology Microwave Sounder (ATMS) on board the S-NPP and JPSS satellites produces a Precipitable Water product. This product is created through the Microwave Integrated Retrieval System (MIRS), which uses the same algorithm for several polar-orbiting satellite microwave sensors. This product is not retrieved as an independent parameter in MiRS but is rather a vertical integration of the retrieved atmospheric moisture profile. MiRS is a well-validated, integrated 1D-VAR retrieval system designed to operate effectively in all weather conditions and over all surface types. It is important to note that the water vapor is transformed into the Logarithmic space before the retrieval. This is done for the two-fold purpose of avoiding the negative values of water vapor, and for making the water vapor distribution Gaussian.1
1Sid-Ahmed Boukabara, Kevin Garrett, and Wanchun Chen. Global Coverage of Total Precipitable Water Using a Microwave Variational Algorithm, IEEE Transactions on Geoscience and Remote Sensing, http://mirs.nesdis.noaa.gov/publications/tgrs-boukabara-2048035-x.pdf